Multicenter comparison of Chiari malformation type I presentation in children versus adults.

OBJECTIVE: Treatment for Chiari malformation type I (CM-I) often includes surgical intervention in both pediatric and adult patients. The authors sought to investigate fundamental differences between these populations by analyzing data from pediatric and adult patients who required CM-I decompression. METHODS: To better understand the presentation and surgical outcomes of both groups of patients, retrospective data from 170 adults and 153 pediatric patients (2000-2019) at six institutions were analyzed. RESULTS: The adult CM-I patient population requiring surgical intervention had a greater proportion of female patients than the pediatric population (p < 0.0001). Radiographic findings at initial clinical presentation showed a significantly greater incidence of syringomyelia (p < 0.0001) and scoliosis (p < 0.0001) in pediatric patients compared with adult patients with CM-I. However, presenting signs and symptoms such as headaches (p < 0.0001), ocular findings (p = 0.0147), and bulbar symptoms (p = 0.0057) were more common in the adult group. After suboccipital decompression procedures, 94.4% of pediatric patients reported symptomatic relief compared with 75% of adults with CM-I (p < 0.0001). CONCLUSIONS: Here, the authors present the first retrospective evaluation comparing adult and pediatric patients who underwent CM-I decompression. Their analysis reveals that pediatric and adult patients significantly differ in terms of demographics, radiographic findings, presentation of symptoms, surgical indications, and outcomes. These findings may indicate different clinical conditions or a distinct progression of the natural history of this complex disease process within each population, which will require prospective studies to better elucidate.

Surgical resection of recurrent intramedullary subependymoma of the cervical spinal cord.

Spinal subependymomas (SE) are rare, often indolent benign tumors presenting most frequently as intramedullary tumors in the cervical spine or cervicothoracic junction. When symptomatic, patients often present with years of sensory changes, weakness, paresthesias, or bowel and bladder dysfunction. Preoperatively, SE are difficult to distinguish radiographically from ependymomas or astrocytomas; however, it is important to make the distinction intraoperatively as complete resection can be curative. Here the authors present a rare case of recurrent, symptomatic cervical subependymoma which underwent gross-total resection and discussion of management strategies and outcomes of all SE at their institution.

Congenital hydrocephalus diagnosed in a nonagenarian: Case report.

Congenital hydrocephalus after peripartum infection usually presents early in life; however, we present a 92-year-old female patient with newly diagnosed hydrocephalus secondary to peripartum infection. Intracranial imaging showed ventriculomegaly, calcifications bilaterally throughout the cerebral hemispheres, and findings suggesting a chronic process. This presentation is most likely to occur in low-resource settings, and given the risks of operation, conservative management was preferred.

Above-The-Hairline Suboccipital Transverse Approach for the Treatment of Chiari I Malformation.

BACKGROUND: Chiari I malformation is a common pediatric neurosurgical disorder with an established treatment paradigm. Posterior fossa decompression and duraplasty (PFDD) is associated with symptom improvement but it carries postoperative risk, particularly cerebrospinal fluid (CSF) leak and wound complications. In addition, the cosmetic outcomes of PFDD have been overlooked in the literature. OBJECTIVE: To describe a novel approach for PFDD in which the transverse surgical incision is completely hidden above the hairline and to report early outcomes in a prospective patient cohort. METHODS: Clinical and cosmetic outcomes were recorded for 15 consecutive pediatric patients who underwent PFDD for Chiari I malformation via the above-the-hairline transverse suboccipital approach. RESULTS: The median clinical follow-up time was 6 months (range 1-12 months), and the majority of patients experienced significant improvement of their preoperative symptoms. Three patients (20%) experienced complications associated with surgery, which included injury to the greater occipital nerve, CSF hypotension and subfascial pseudomeningocele, and superficial wound dehiscence that resolved spontaneously with oral antibiotics. Zero patients (0%) returned to the operating room for persistent CSF leak, deep wound infection, or revision decompression. An excellent cosmetic outcome was achieved in 12 patients (80%). No patient had a poor cosmetic outcome. CONCLUSION: The above-the-hairline transverse suboccipital approach for PFDD in patients with Chiari I malformation offers favorable cosmetic outcomes and fascial closure while permitting adequate decompression.

Utilizing pre- and postoperative radiological parameters to predict surgical outcomes following untethering for tethered cord syndrome in a pediatric population.

OBJECTIVE: Tethered cord syndrome (TCS) can lead to significant downstream neurological deficits including gait deterioration, incontinence, and often unexplained chronic low-back pain. Surgical intervention may relieve symptoms, but there are no defined radiological parameters associated with surgical outcomes and functional status. The authors aimed to define pre- and postoperative radiological parameters for assessing surgical outcomes in TCS. METHODS: The authors performed a single-center retrospective review of all pediatric patients treated for TCS between 2016 and 2021. Patient baseline characteristics and operative metrics included age, sex, level of conus, level of procedure, tethering pathology, symptoms at presentation, complications, improvement of symptoms, and reoperation rate. MRI measurements included pre- and postoperative anterior canal distance (ACD) and bending angle (BA). RESULTS: Thirty-three pediatric patients were identified who underwent untethering of the spinal cord and had pre- and postoperative MRI between 2016 and 2021. The mean patient age was 5.64 ± 5.33 years. Twenty patients (60.60%) were female. Regarding the site of untethering, 31 procedures (93.93%) were performed at the lumbosacral region and 2 (6.06%) were performed at the thoracolumbar region. The conus medullaris was found above L3 in 21.21% of patients. Postoperatively, 18.18% of patients experienced complications, 48.48% showed improvement in their symptoms, and 48.48% were equivocal or had persistent symptoms. The mean preoperative ACD0 (measured from the posterior vertebral body margin [middle] to the anterior margin of the conus medullaris) was 6.15 ± 3.18 mm, the postoperative ACD0 was 2.25 ± 2.72 mm, and the average change in ACD0 was -0.90 ± 1.31 mm. The mean preoperative BA was 26.00° ± 11.56°, the mean postoperative BA was 15.92° ± 9.81°, and the average change in BA was -10.08° ± 8.80°. An optimal cutoff value for preoperative BA to predict reoperation in pediatric patients with complex TCS undergoing surgery was ≥ 31.70° (area under the curve = 0.83). CONCLUSIONS: In surgically treated patients with TCS, certain preoperative radiological parameters may be important in predicting postoperative surgical outcomes; these parameters can be evaluated and reported to indicate patients at high risk for complications. Further prospective multicenter research is warranted to offer robust evidence of association of patient outcomes with preoperative radiological parameters in TCS.

Posterior communicating artery infundibulum with oculomotor nerve palsy treated with microvascular decompression: a case report and 2-dimensional technical operative video.

Oculomotor nerve palsies are typically associated with posterior communicating artery (PcommA) aneurysms. We report a rare case of an oculomotor nerve palsy caused by a PcommA infundibular dilatation. Although there are cases of infundibular dilatations causing cranial nerve palsies, only reports of three involving the PcommA exists. We review these reported cases in the literature and discuss their treatments as well as other non-aneurysmal compressive etiologies that may cause oculomotor nerve palsies. We present the case of a 53-year-old female with transient oculomotor nerve palsy that was initially diagnosed with a PcommA aneurysm. She underwent a craniotomy with plans of microsurgical clipping; however, the dilatation was identified correctly as an infundibulum intraoperatively. The operation was completed as a microvascular decompression and her oculomotor nerve palsy has not returned at the 1-year follow-up. We provide a detailed microsurgical report and video detailing the operative technique and relevant anatomy for this operation. Although rare and not as life-threatening as aneurysms, infundibular dilatations as a cause of oculomotor nerve palsy should remain as a differential diagnosis. Given the difference in natural history and treatment of these two entities, it is important to diagnose and treat them appropriately. Multimodal imaging such as thin-sliced computed tomography angiogram (CTA) and 3-dimensional (3D) rotational angiography can aid in diagnosis.

The Impact of Major Military War Campaigns on Neurosurgery: Informetric Data and Time-Trend Analysis.

BACKGROUND: Given the neurotrauma that soldiers might face during wars, a byproduct of such devastating neurosurgical conditions can be novel data, which can act as a catalyst for potentially paradigm-shifting research. We aimed to identify the impact of major U.S. military campaigns on military neurosurgery literature across defined time periods. METHODS: A comprehensive Elsevier's Scopus database search was performed to capture all published and indexed studies from 1915 to 2021 relevant to military neurosurgery. A discrete set of validated informetric metadata parameters were extracted and analyzed using productivity analysis, citation analysis, keyword analysis, text mining, content analysis, and collaboration network mapping. RESULTS: Our search yielded 2216 documents. Annual scientific production since 1915 grew at a compounded rate of 6.1% per year, with the most significant increases during U.S. military campaigns (coefficient = 42.9, P < 0.001) and following the introduction of the Department of Defense Trauma Registry in 2007 (coefficient = 114.5; P < 0.001). Each war had a direct influence on military neurosurgery literature growth (P < 0.05), with the most prominent following the Afghanistan war. The journals with the most publications on military neurosurgery were Military Medicine (n = 168) and Journal of Head Trauma. The topmost cited author was Hoge et al. (N = 2083), while the topmost cited country was the United States (N = 1098). CONCLUSIONS: Since World War II, the military has contributed significant historical developments to neurosurgery, the most prominent being after the Iraq and Afghanistan wars and the introduction of the Department of Defense Trauma Registry.

Streamlining the External Ventricular Drain and Intracranial Pressure Monitor Procedural Setup: A Quality Improvement Initiative.

OBJECTIVE: External ventricular drain (EVD) and intracranial pressure (ICP) monitor placements are among the most common critical care procedures for severe brain injury. Quality improvement initiatives have streamlined similar processes. The aim of the project was to decrease the time to collect supplies for EVD or ICP monitor placement by 25% by April 1, 2021. METHODS: The project followed the define-measure-analyze-improve-control 6 sigma framework. Several quality gaps were identified: equipment stored separately, delays in replacing faulty items, and wasted resources. The team defined the process using the suppliers-inputs-processes-outputs-customers + requirements method, measured time to collect supplies, and analyzed data with an Ishikawa/fishbone diagram. The improve phase included a kaizen burst to generate solutions and an impact/effort grid to evaluate options. The team concluded that the optimal plan was to stock a mobile EVD cart and an ICP monitor pole with disposable go-bags. RESULTS: The average time for nurses to collect EVD placement supplies decreased from 411 to 63 seconds (7-1 minute), and the average time for nurses to collect ICP monitor placement supplies decreased from 418 to 53 seconds (7-<1 minute). Residents decreased the time to obtain EVD placement supplies from 330 to 56 seconds (6-<1 minute) and ICP monitor supplies from 489 to 77 seconds (8-1 minute). Feedback was overwhelmingly positive and focused on improved process efficiency and reduced waste. CONCLUSIONS: The time reduction and enthusiasm are likely associated with the simplicity and comprehensiveness of the intervention design. Including key stakeholders in decision-making and succinct communications reduced resistance to change.

Elevated Electrode Impedances During Deep Brain Stimulation Surgery May Be Due to Peri-Electrode Air Collections.

Deep brain stimulation (DBS) is a commonly used treatment for medically refractory movement disorders and epilepsy. Intraoperative testing of electrode impedances is routinely done during DBS surgery to identify electrical conduction defects in the system. We present two illustrative cases involving elevated intraoperative impedances. In the first case, the temporal evolution of impedance changes and a postoperative head CT were consistent with a small and slowly resolving air collection along the lead. In the second case, an abnormally high impedance reading was observed at a single electrode and then "transferred" to be observed at an adjacent electrode upon adjustments of the electrode position, likely due to small air collection at a fixed position in the brain tissue. In both cases, careful troubleshooting allowed identification of the issue and avoidance of unnecessary surgical revisions. A thorough understanding of the possible sources of, and troubleshooting for, abnormal impedance readings is needed for effective intraoperative DBS monitoring.

Anterior lumbar interbody fusion: single institutional review of complications and associated variables.

BACKGROUND CONTEXT: As more patients undergo anterior lumbar interbody fusion (ALIF) procedures and more devices are created for that purpose, it is important to understand the complications that can arise and the variables that mitigate risk for major and minor complications. PURPOSE: To assess complication rates after ALIF with or without posterior instrumentation and variables associated with increased likelihood of postoperative complications. We aim to provide this data as benchmarking to improve patient safety and surgical care. STUDY DESIGN: A single-center retrospective cohort study. PATIENT SAMPLE: All adult patients who underwent ALIF between 2017 and 2019 was performed OUTCOME MEASURES: Post-operative major and minor complications were evaluated. METHODS: Complications were recorded and presented as percentages. Patient demographics, perioperative, and postoperative data were also collected and analyzed between patients who had no complications and those that had any complication. Subgroup analysis of surgical complications were performed by nonparametric Chi-square tests. Continuous variables were compared using Mann-Whitney U tests. RESULTS: Ninty-five of three hundred sixty-two (26.2%) of patients experienced a minor or major complication. Among the most common complications found were surgical site infections (5.8%), neurological complications (4.1%), vascular complications (3.6%), and urinary tract infections (3.3%). Patients undergoing ALIF alone with post-operative complications had higher mean age, higher BMI, higher ASA status, and experienced higher estimated blood loss. Patients undergoing ALIF and posterior instrumentation with post-operative complications were more likely to have diabetes and had a higher ASA status. Patients with any complications from both groups had longer length of stay, discharge to a non-home setting and were more likely to be readmitted or return to the operating room. CONCLUSION: Our study reveals variables associated with complications at our institution, including age of the patient, BMI, and ASA status leading to higher complications and greater LOS, higher readmission rates, and disposition to skilled facilities.

International trends in grant and fellowship funding awarded to women in neurosurgery.

OBJECTIVE: Metric tracking of grant funding over time for academic neurosurgeons sorted by gender informs the current climate of career development internationally for women in neurosurgery. METHODS: Multivariate linear trend analysis of grant funding awarded to neurosurgeons in the NIH and World Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER) was performed. Traveling fellowships for international neurosurgery residents sponsored by the AANS and Congress of Neurological Surgeons (CNS) were also analyzed. RESULTS: Within the US, funding awarded to female neurosurgeons has remained static from 2009 to 2019 after adjusting for inflation and overall trends in NIH funding (ß = -$0.3 million per year, p = 0.16). Internationally, female neurosurgeons represented 21.7% (n = 5) of project leads for World RePORTER grants. Traveling fellowships are also an important building block for young international female neurosurgeons, of which 7.4% (n = 2) of AANS international traveling fellowships and 19.4% (n = 7) of AANS/CNS pediatrics international traveling fellowships are women. CONCLUSIONS: Over the past decade, funding has increased in neurosurgery without a concordant increase in funding awarded to women. Recognition of this trend is essential to focus efforts on research and career development opportunities for women in neurosurgery. Worldwide, female neurosurgeons head one-fifth of the funded project leads and constitute a minority of international traveling fellowships awarded by organized neurosurgery.

Bilateral Subdural Hygromas After Deep Brain Stimulation Implantation in the Setting of Unrecognized Intracranial Hypotension.

Cerebrospinal fluid (CSF)-venous fistulas are a recently recognized cause of spontaneous spinal CSF leak and present most commonly with Valsalva ("cough")-exacerbated or orthostatic headaches. By inducing CSF hypotension, they cause diffuse pachymeningeal enhancement and brain sag on MRI. This unusual case demonstrates the potential for bilateral subdural hygroma development in a patient with an undiagnosed CSF-venous fistula after ventral intermediate nucleus (VIM) deep brain stimulation (DBS) implantation. A 68-year-old gentleman with medically-refractory essential tremor underwent extensive preoperative evaluation by the Mayo Clinic-Rochester DBS Committee. Initial MRI during preoperative evaluation had no evidence of CSF hypotension, but MRI performed the day before surgery demonstrated diffuse pachymeningeal enhancement. He underwent bilateral VIM DBS implantation and presented in the subacute postoperative period with bilateral subdural hygromas. Further testing identified a prominent hyperdense paraspinal vein arising from the T10/T11 nerve root, consistent with CSF-venous fistula. Even when patients undergo rigorous preoperative evaluations for surgical procedures, insidious pathologies can develop and cause unexpected postoperative complications.

Surgery versus radiosurgery for facial nerve schwannoma: a systematic review and meta-analysis of facial nerve function, postoperative complications, and progression.

OBJECTIVE: Intracranial facial nerve schwannomas (FNS) requiring treatment are frequently recommended for surgery or stereotactic radiosurgery (SRS). The objective of this study was to compare facial nerve function outcomes between these two interventions for FNS via a systematic review and meta-analysis. METHODS: A search of the Ovid EMBASE, PubMed, SCOPUS, and Cochrane databases from inception to July 2019 was conducted following PRISMA guidelines. Articles were screened against prespecified criteria. Facial nerve outcomes were classified as improved, stabilized, or worsened by last follow-up. Incidence was pooled by random-effects meta-analysis of proportions. RESULTS: Thirty-three articles with a pooled cohort of 519 patients with FNS satisfied all criteria. Twenty-five articles described operative outcomes in 407 (78%) patients; 10 articles reported SRS outcomes in 112 (22%). In the surgical cohort, facial nerve function improved in 23% (95% CI 15%-32%), stabilized in 41% (95% CI 32%-50%), and worsened in 30% (95% CI 21%-40%). In the SRS cohort, facial nerve function was improved in 20% (95% CI 9%-34%), stable in 66% (95% CI 54%-78%), and worsened in 9% (95% CI 3%-16%). Compared with SRS, microsurgery was associated with a significantly lower incidence of stable facial nerve function (p < 0.01) and a significantly higher incidence of worsened facial nerve function (p < 0.01). Tumor progression and complication rates were comparable. Outcome certainty assessments were very low to moderate for all parameters. CONCLUSIONS: Unfavorable facial nerve function outcomes are associated with surgical treatment of intracranial FNS, whereas stable facial nerve function outcomes are associated with SRS. Therefore, SRS should be recommended to patients with FNS who require treatment, and surgery should be reserved for patients with another indication, such as decompression of the brainstem. Further study is required to definitively optimize and validate management strategies for these rare skull base tumors.

A cross-sectional analysis of variables associated with morbidity and mortality in postoperative neurosurgical patients diagnosed with sepsis.

BACKGROUND: Sepsis is a systemic, inflammatory response to infection associated with significant morbidity and mortality. There is a considerable lack of literature exploring sepsis in neurosurgery. We aimed to identify variables that were correlated with mortality and increased morbidity as defined by readmission and increased length of stay in postoperative neurosurgical patients that met a sepsis diagnosis. METHODS: A retrospective chart review was conducted of 105 patients who underwent a neurosurgical operation at our institution from 2012 to 2017 who were discharged with at least one sepsis diagnosis code and who did not have a preoperative infection. We identified variables that were correlated with mortality, readmission, and increased length of stay. RESULTS: Patients who survived were preferentially distributed towards lower ASA Physical Status Classification scores. A larger percentage of patients who did not survive had cranial surgery, whereas patients who survived were more likely to have undergone spinal surgery. Higher respiratory rates, higher maximum lactic acid levels, positive sputum cultures, and lower incoming Glasgow Coma Scores (GCS) were significantly correlated with mortality. A larger fraction of readmitted patients had positive surgical site cultures but had negative sputum cultures. Length of hospitalization was correlated with incoming GCS, non-elective operations, and Foley catheter, arterial line, central line, and endotracheal tube duration. CONCLUSIONS: Neurosurgical postoperative patients diagnosed with sepsis may be risk stratified for mortality, readmission, and increased length of stay based on certain variables that may help direct their care. Further prospective studies are needed to explore causal relationships.

Polymicrobial Intracerebral Abscess Growing Mycobacterium avium Complex and Achromobacter xylosoxidans: Case Report and Literature Review.

BACKGROUND: Mycobacterium avium complex (MAC) and Achromobacter xylosoxidans (AX) are uncommon sources of neurosurgical infections, particularly in immunocompetent hosts. We report the first published case of intracranial AX abscess and polymicrobial AX-MAC abscess, as well as the fourth MAC abscess in a non-immunocompromised patient. METHODS: This case report was conducted via retrospective chart review. A literature review was completed in compliance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. RESULTS: Ten years following mucocele resection, a 60-year-old man presented with sinus congestion and headache. Head imaging revealed a left frontal lesion abutting the cribriform plate and ethmoid roof. The patient had a left frontal craniotomy for abscess drainage. Intraoperative cultures demonstrated polymicrobial growth of AX and MAC, managed with antimicrobial therapy and staged skull base reconstruction. Three cases of MAC abscess and 16 cases of AX ventriculitis or meningitis have been reported in immunocompetent patients. All MAC cerebral abscesses occurred in adults, one of whom succumbed to the infection. Of the 9 AX meningitis cases, 4 occurred in neonates and 2 in pediatric patients. Six of the 7 AX ventriculitis cases occurred after neurosurgical operations at the same hospital from contaminated chlorhexidine basins. Except for the neonates, AX ventriculitis or meningitis patients had undergone neurosurgery or had a history of cranial trauma. There were no reports of polymicrobial AX-MAC intracranial abscess. CONCLUSIONS: AX and MAC are rare causes of intracranial infection. Patients with these pathogens identified in the central nervous system require a multidisciplinary approach for successful management.

Primary cervical spine AL-κ amyloidoma: A case report and review of the literature.

Of the myriad of variants of amyloidoses where abnormally folded proteins damage native tissue, primary cervical spine amyloidoma represents one of the rarest forms. Since clinical presentations and imaging findings appear similar to other pathologies, including abscesses, metastatic lesions, and inflammatory lesions, a definitive diagnosis requires a biopsy with specific immunohistochemical stains. We present the first known case of primary cervical amyloid light-chain (AL)-κ subtype amyloidoma and compare the clinical presentations, imaging findings, treatment options, and immunohistochemical subtypes of primary, hemodialysis, and multiple myeloma cervical amyloidomas. Our case is of a 58-year-old man who developed neck pain radiating to the left arm with bilateral upper extremity weakness over several months. Magnetic resonance imaging revealed a circumferential C1-C2 mass extending into the neural foramina inducing severe mass effect. The patient underwent C2 laminectomy and resection of the lesion which was discovered during surgery to be completely epidural. Postoperatively, his pain and weakness improved. A complete work-up was negative for systemic amyloidosis or inflammatory conditions. In the setting of a long clinical history of hemodialysis, this patient required specific staining and laboratory testing to correctly diagnose his primary cervical AL-κ subtype amyloidoma. Cervical amyloidomas comprise a very small minority of amyloid pathology with an exceptional prognosis following successful surgical resection and stabilization. It is recommended these patients undergo surgical resection with appropriate characterization and a complete work-up to rule out systemic disease.